Isaac Mattson

Isaac Mattson

29-Year-Old PitcherRP
Pittsburgh Pirates
2025 Fantasy Outlook
There was no outlook written for Isaac Mattson in 2025. Check out the latest news below for more on his current fantasy value.
$Signed a one-year contract with the Pirates in December of 2024.
Recalled by Pittsburgh
PPittsburgh Pirates
June 7, 2025
The Pirates recalled Mattson from Triple-A Indianapolis on Saturday.
ANALYSIS
Mattson has appeared in three games for the Pirates this season, but he has spent most of the year in Triple-A, where he has a 2.42 ERA, 0.95 WHIP, four saves and a 27:6 K:BB across 22.1 innings. He'll take the spot in the Pirates' bullpen vacated by Joey Wentz, who was designated for assignment in a corresponding move.
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Pitching Stats
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2025
2024
2021
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2024 MLB Game Log
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2021 MLB Game Log
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Pitching Appearances Breakdown
Average Pitch Count
15
Last 10 Games
15
Last 5 Games
15
How many pitches does Isaac Mattson generally throw?
 
1-10
 
11-20
 
21-30
 
31-40
 
41-50
 
51-60
 
61-70
 
71-80
 
81-90
 
91-100
 
101-110
 
111-120
 
121+
 
1-10
 
11-20
 
21-30
 
31-40
 
41-50
 
51-60
 
61-70
 
71-80
 
81-90
 
91-100
 
101-110
 
111-120
 
121+
 
1-10
 
11-20
 
21-30
 
31-40
 
41-50
 
51-60
 
61-70
 
71-80
 
81-90
 
91-100
 
101-110
 
111-120
 
121+
What part of the game does Isaac Mattson generally pitch?
 
 
 
1st
 
 
 
2nd
 
 
 
3rd
 
 
 
4th
 
 
 
5th
 
 
 
6th
 
 
 
7th
 
 
 
8th
 
 
 
9th
 
Extra
 
 
 
1st
 
 
 
2nd
 
 
 
3rd
 
 
 
4th
 
 
 
5th
 
 
 
6th
 
 
 
7th
 
 
 
8th
 
 
 
9th
 
Extra
 
 
 
1st
 
 
 
2nd
 
 
 
3rd
 
 
 
4th
 
 
 
5th
 
 
 
6th
 
 
 
7th
 
 
 
8th
 
 
 
9th
 
Extra
% Games Reaching Innings Threshold
% Games By Number of Innings Pitched
Left/Right Pitching Splits
Since 2023
 
 
-11%
BAA vs RHP
2025
 
 
-100%
BAA vs RHP
2024
 
 
-100%
BAA vs LHP
2023
No Stats
BAA Batters K BB H 2B 3B HR
Since 2023vs Left .071 15 7 1 1 0 0 1
Since 2023vs Right .063 22 4 5 1 0 0 0
2025vs Left .200 5 3 0 1 0 0 1
2025vs Right .000 9 2 1 0 0 0 0
2024vs Left .000 10 4 1 0 0 0 0
2024vs Right .125 13 2 4 1 0 0 0
2023vs Left 0 0 0 0 0 0 0 0
2023vs Right 0 0 0 0 0 0 0 0
More Splits View More Split Stats
Home/Away Pitching Splits
Since 2023
 
 
-100%
ERA on Road
2025
 
 
-100%
ERA on Road
2024
 
 
-100%
ERA on Road
2023
No Stats
ERA WHIP IP W L SV K/9 BB/9 HR/9
Since 2023Home 6.75 1.31 5.1 1 0 0 10.1 8.4 1.7
Since 2023Away 0.00 0.25 4.0 0 0 0 11.3 2.3 0.0
2025Home 2.25 0.50 4.0 1 0 0 11.3 2.3 2.3
2025Away 0 0 0 0 0 0 0 0 0
2024Home 20.25 3.75 1.1 0 0 0 6.8 27.0 0.0
2024Away 0.00 0.25 4.0 0 0 0 11.3 2.3 0.0
2023Home 0 0 0 0 0 0 0 0 0
2023Away 0 0 0 0 0 0 0 0 0
More Splits View More Split Stats
Stat Review
How does Isaac Mattson compare to other relievers?
This section compares his stats with all relief pitcher seasons from the previous three seasons (minimum 30 innings)*. The bar represents the player's percentile rank. For example, if the bar is halfway across, then the player falls into the 50th percentile for that stat and it would be considered average.

* Exit Velocity, Barrels/BBE %, Balls Hit 95+ MPH %, and Spin Rate are benchmarked against 2019 data (min 30 IP). See here for more exit velocity/barrels stats plus an explanation of current limitations with that data set.
  • K/BB
    Strikeout to walk ratio.
  • K/9
    Average strikeouts per nine innings.
  • BB/9
    Average walks per nine innings.
  • HR/9
    Average home runs allowed per nine innings.
  • Fastball
    Average fastball velocity.
  • ERA
    Earned run average. The average earned runs allowed per nine innings.
  • WHIP
    Walks plus hits per inning pitched.
  • BABIP
    Batting average on balls in play. Measures how many balls in play against a pitcher go for hits.
  • GB/FB
    Groundball to flyball ratio. The higher the number, the more likely a pitcher is to induce groundballs.
  • Left On Base
    The percentage of base runners that a pitcher strands on base over the course of a season.
  • Exit Velocity
    The speed of the baseball as it comes off the bat, immediately after a batter makes contact.
  • Barrels/BBE
    The percentage of batted ball events resulting in a Barrel. A Barrel is a batted ball with similar exit velocity and launch angle to past ones that led to a minimum .500 batting average and 1.500 slugging percentage.
  • Spin Rate
    Spin Rate is the rate of spin on a baseball after it is released. It is measured in revolutions per minute (rpm).
  • Balls Hit 95+ MPH
    The percentage of batted balls hit that met or exceeded the 95 MPH threshold.
  • Swinging Strike
    The percentage of pitches that result in a swing and a miss.
K/BB
5.00
 
K/9
11.3
 
BB/9
2.3
 
HR/9
2.3
 
Fastball
92.6 mph
 
ERA
2.25
 
WHIP
0.50
 
BABIP
.000
 
GB/FB
0.14
 
Left On Base
166.7%
 
Exit Velocity
86.5 mph
 
Barrels/BBE
20.0%
 
Spin Rate
2060 rpm
 
Balls Hit 95+ MPH
30.0%
 
Swinging Strike
13.3%
 
Advanced Pitching Stats
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Defensive Stats
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Stats Vs Today's Lineup
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More Fantasy News
Optioned to Triple-A
PPittsburgh Pirates
May 26, 2025
The Pirates optioned Mattson to Triple-A Indianapolis on Monday, Noah Hiles of the Pittsburgh Post-Gazette reports.
ANALYSIS
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Promoted Tuesday
PPittsburgh Pirates
May 20, 2025
The Pirates selected Mattson from Triple-A Indianapolis on Tuesday.
ANALYSIS
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Returns to Pittsburgh
PPittsburgh Pirates
December 5, 2024
Mattson signed a minor-league contract with the Pirates on Thursday, Noah Hiles of the Pittsburgh Post-Gazette reports.
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Removed from 40-man roster
PPittsburgh Pirates
November 4, 2024
The Pirates outrighted Mattson to Triple-A Indianapolis on Monday, Andrew Destin of the Pittsburgh Post-Gazette reports.
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Selected from Triple-A
PPittsburgh Pirates
September 19, 2024
The Pirates selected Mattson was selected from Triple-A Indianapolis on Thursday, Noah Hiles of the Pittsburgh Post-Gazette reports.
ANALYSIS
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Latest Fantasy Rumors
Returning to big club?
PPittsburgh Pirates
June 7, 2025
Mattson has a locker in the Pirates' clubhouse ahead of Saturday's contest against the Phillies, Danny Demilio of PittsburghBaseballNow.com reports.
ANALYSIS
Mattson appeared in three games for the Pirates and allowed a solo home run and one walk while striking out four batters across three innings before being optioned to Triple-A Indianapolis on May 26. He's spent most of the 2025 season in Triple-A, where he has a 2.42 ERA, 0.95 WHIP, four saves and a 27:6 K:BB across 22.1 innings. Joey Wentz's locker is not in Pittsburgh's clubhouse, and he may be the corresponding move to make room on the 26-man roster for Mattson, per Demilio.
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